Catalytic conversion apparatus



March 10, 1953 J. 5. PALMER 2,631,090

CATALYTIC CONVERSION APPARATUS Original Filed Aug. 16, 1950 FIG. I. FIG. 2.

I DEN PHASE INVENTOR. Jewell S. Palmer,

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Patented Mar. 10, 1953 CATALYTIC CONVERSION APPARATUS Jewell S. Palmer, Baytown, Tex., assignor, by

mesne assignments, to Standard Oil Development Company, Elizabeth, N. 3., a corporation of Delaware Original application August 16, 1950, Serial No.

179,838. Divided and this application November 17, 1951, Serial No. 256,911

1 Claim.

The present invention is directed to apparatus in which a conversion operation may be conducted in the presence of finely divided fluidized solids. The invention is particularly directed to apparatus for catalytic conversion operations, such as catalytic cracking of hydrocarbons, and the like.

This application is a division of Serial No. 179,838, entitled Apparatus for Conducting Conversion Operations filed August 16, 1950, for Jewell S. Palmer. The parent application Serial No. 179,838 is directed to the embodiments of Figs. 1, 2, 3, and 5 of the drawing and the present application is directed to the embodiment of Fig. 4 of the drawing.

The apparatus of the present invention comprises a reaction vessel such as an elongated re action vessel in the lower portion of which is an inlet line through which a suspension of finely divided solids may be introduced thereto. Arranged in the upper end of the vessel is an outlet through which finely divided solids in a gasiform suspension may be withdrawn. The vessel is so operated that a dense phase of finely divided solids in a gasiform suspension is maintained therein below a dispersed phase. The outlet is provided with means in a passageway leading thereto, such as a valve, for controlling the flow of suspension therethrough. The level of the dense phase in the elongated vessel may be controlled by means for withdrawing suspension containing finely divided solids from a point immediately above the normal level of the dense phase into said outlet.

The means for varying the flow of suspension through said outlet may include a valve in a passageway leading to said outlet arranged either interiorly or exterior-1y to said vessel. In short, the outlet may have a valve arranged therein inside of the vessel or outside thereof. Similarly, the means for withdrawing suspension from immediately above the dense phase may include a downwardly projecting extension of said outlet in which is arranged at least one passageway which may be a plurality of slotted passageways or may be a plurality of orifices. In either case, the passageway or ways will be arranged immediately above and below the dense phase level in said vessel. Alternatively, rather than the outlet being provided with a downwardly projecting extension member, the vessel may have arranged, on the exterior thereof, a plurality of conduits fluidly communicatin the interior of said vessel at points above and below said dense phase with said outlet. A further modification of my invention embodies another passageway arranged in said extension to said outlet at an upper point in said vessel and means for opening and closing said outlet.

The invention will be further described by reference to the drawing in which Fig. 1 is a cross-sectional view of one embodiment thereof with an elongated reaction vessel provided with an inlet and an outlet and a downwardly extending extension of said outlet with means for raising and lowering said downwardly extending member;

Fig. 2 is a modification of the embodiment of Fig. 1 wherein the downwardly extending member is provided with a passageway at the upper end thereof and means for opening and closing said passageway.

Fig. 3 is a still further modification of the present invention whereby the flow through the out let is varied by means of a plurality of conduits with valve means arranged therein;

Fig. 4 is a still further embodiment of the present invention wherein the downwardly extending member is replaced by a plurality of conduits exterior to the vessel communicating the interior thereof with the outlet; and

Fig. 5 is a still further modification of Figs. 1 to 3, inclusive, where the slotted passageway is replaced by a plurality of orifices arranged in the downwardly extending projecting member.

Referring now to the drawing, in which identical parts will be identified by identical numbers, and especially to Fig. l, numeral II designates an elongated reaction vessel such as a catalytic cracking reactor in which a dense phase of catalyst, indicated by the shaded portion i2, is maintained by adjustment of velocity therein. Above the dense phase of the catalyst a disperse phase I3 of catalyst is maintained. The vessel II is provided with an inlet I4 and an outlet I5. As an extension of outlet IS, a downwardly projecting extension member or dip leg I6 projects below the surface of the dense phase I2 and connects the outlet I5 therewith. The clip leg or downwardly projecting extension member I6 defines a slotted passageway I! which may extend from the bottom open end thereof to a point well above the normal level of dense phase I2. It will be understood that slotted passageway I! may be a plurality of slotted passageways. The downwardly projecting member or dip leg I6 is held in juxtaposition with outlet I5 by a movable support I8 which is so arranged with stuifing boxes I9 to allow raising and lowering of dip leg I6. The movable supports may be actuated to raise or lower dip leg 5 manually or by suitable power means such as fluid operated motors, hy draulic cylinders, electrically operated means, and the like. These means are not shown. Dip leg 26 and outlet is define an annular passageway 26 fluidly communicating the disperse phase 13 with outlet IS. The lower end of outlet [5 and the upper end of dip leg l6 are provided with erosion shoes 2i to prevent erosion of these parts of the apparatus on passage of suspension of finely divided solids therethrough.

Referring now to Fig. 2, it will be seen that this modification of my invention is generally similar to Fig. 1 but differs in that the dip le or extension member I8 is made an integral part.

of outlet [5 as a downwardly extending projection thereof. At the upper end of dip leg is there is defined an outwardly projecting conduit 39 which communicates the disperse phase I 3 in veS- sel Ii with the interior of extension member 16. Conduit 30 may conveniently be a plurality of conduits defining a plurality of passageways but only one is shown for briefness of description. Flow through this passageway 39 is controlled by a valve 3! which may be operated from the exterior of the vessel.

A still further modification of the present in vention is illustrated in Fig. 3 in which the vessel H is provided with a conduit Eli in which is arranged a valve or flow control member 32. Conduit Ml communicates the upper interior of vessel i l with outlet 15 and allows passage of suspension from the disperse phase (3 to outlet It.

A still further embodiment of the invention is illustrated in Fig. 4 in which the extension member 01' dip leg 16 is dispensed with. In this modification of my invention the outlet 55 is provided with a control valve 5% arranged in out let it: exterior to vessel H and a plurality of conduit-s 5! are arranged on the exterior of vessel I! at points above and below the level of dense phase 12 therein. These conduits 5i discharge into a common manifold or conduit 52 which, in turn, discharges into outlet l5 at a point downstream from valve 50.

In Fig. 5 a still further modification of my invention is presented in which the dip leg 5 defines a plurality of orifices 60 which are arranged above and below the normal upper level of dense phase I2 as shown. In this modification of my invention the valve or means for controlling the flow through outwardly projecting conduit 38 is shown as a valve 6| arranged in member on the interior of the vessel. Similar to Fig. 2 conduit 36 may be a plurality of conduits each controlled by separatevalve-means defining a plurality of controlled passageways.

In conducting reactions in vessels similar to those illustrated in the several figures of the drawing, for example, catalytic cracking operations, all of the fluidized catalyst fed to the reaction vessel, as a suspension of finely divided solids in the vaporized hydrocarbon, must pass out of the top of the reactor with the cracked hydrocarbon vapors as a suspension therein. As a result the depth of the catalyst bed is depe de t upon the velocity of vapors through the reactor and is not readily controllable by means conventional to the art. In the device illustrated in Fig. 1 or the drawing, the slotted dip pipe i6 is open at both the top'and the bottom and is provided with suitable means for raising and lowering this pipe. Thus in operation with dip pipe 5 at its lowest position substantially all the vapors and catalyst will pass outside the dip pipe and through the open space between the top of dip pipe 1'6 and the outlet l5 indicated by numeral 26 and thus leave the reactor through outlet [5. In this position the vessel will operate at its maximum dense phase level. By raising the dip pipe N5 the opening 20 is reduced and the pressure drop through this space 26 is thereby increased. When this is done additional uantities of vapors and catalyst pass through the slot H and up through dip pipe [5 and outwardly through outlet 15. This results in lowering the bed level in the vessel and thus the catalyst holdup or retention time in the reaction vessel may be controlled.

The embodiment of Fig. 2 operates in a similar manner. Instead of raising or lowerin the extension member Hi, the valve 35 may be opened or closed. When the valve 3! is at its maximum open position the dense phase 52 will be at its maximum height. By closing this valve or adjusting it towards a closed position, the level of dense phase i2 may be varied at will.

The modification of Fig. 3 operates similarly to that of Figs. 1 and 2 except in this instance a conduit all is provided. By operating valve 42 the amount of suspension passing through conduit 439 into outlet i5 is decreased thus causing more suspension to pass through the slotted passageway i? and thus lowering the level of the dense phase 12 in vessel ii.

The embodiment of Fig. 4, in which the extension member or dip leg i5 is dispensed with, operates in a similar manner with the other embodiments. In this mode of operation the valve Sill may be partially closed causing the suspension to pass through the conduits 5! above the dense phase 42 in reactor H. While not shown in Fig. i, it is to be understood that the conduits 51 may be provided with valves to allow further justmen't of the flow therethrough.

The modification of the present invention of Fig. 5 operates generally similar to the embodiments of Figs. 1 to 4, the only difierence being that, instead of a slot II, a plurality of orifices iii) are provided. In this embodiment the adjustment of valve El toward the closed position causes more of the suspension to pass through the orifice 60 above the dense phase 12 and outwardly through outlet l5 and thereby lowering the level of the dense phase 2.

The invention may be further illustrated with relation to a commercial unit having a capacity of 33,000 barrels per day of hydrocarbon feed stock and products. Through the equivalent of reactor H and extension member 6 may pass 30 tons of finely divided catalyst having particle diameters in the range of 0 to 200 microns with the major portion of the catalyst having particle diameters in the range of 20 to microns. Suitable catalysts include silica-alumina; silicamagnesia, silica-zirconia, alumina and other finely divided particles. The slots 1 I may be two 2-inch slots or four 1-inch slots or may be spaced at intervals and having a width of 1 inches per slot. The dimensions of the slots or perforations or orifices, as the case may be, should be adjusted to give a superficial gas velocity through the slot and up the dip leg in the range from about 25 to feet per second. Good results may be obtained at a gas fiow equivalent to a velocity of 70 feet per second through the open area of the slot in the disperse phase. Actual operations have been conducted in the operating unit hav ing a capacity of 33,000 barrels per day with a gas velocity through the slot of 70 feet per second.

The invention is not restricted to catalytic cracking operations but may be applied to any operations in which a suspension of finely divided solids is introduced into a reaction vessel and a suspension of finely divided solids removed therefrom. As examples of such operations besides catalytic cracking operations may be mentioned the synthesis of hydrocarbons and oxygenated organic compounds from carbon monoxide and hydrogen by contact with a synthesis catalyst, such as promoted iron oxide in finely divided form, the catalytic oxidation of hydrocarbons, the synthesis of oxygenated compounds by the socalled Oxo process and many other reactions, either catalytic or non-catalytic, too numerous to mention here. As an example of a non-catalytic operation, in which the present invention may be employed, may be mentioned the gasification of coal and the recovery of hydrocarbons from shales in finely divided form.

The nature and objects of the present invention having been fully described and illustrated, what I wish to claim as new and useful and to secure by Letters Patent is:

Apparatus for conducting catalytic conversion operations in which a dense phase of finely divided fluidized catalytic solids is maintained below a disperse phase of said solids which comprises, in combination, a vertically elongated vessel in which the only exposed surfaces in the vessel are 30 the interior walls of the vessel, said vessel having as sole openings communicating with its interior an inlet opening at its lower end, an outlet opening at its upper end and a plurality of vertically spaced side ports at points intermediate the upper and lower ends of said vessel, a first conduit connected to the lower end of the vessel and communicating with the inlet opening for conveyance thereto of a suspension of finely divided catalytic solids in gasiform medium, a second conduit connected to the upper end of the vessel and communicating with the outlet opening for removal therefrom of a suspension of finely divided solids in a gasiform medium, a valve in said second conduit exteriorly of said vessel for varying the fiow of suspension through said second conduit, a third conduit connecting to said second conduit above said valve and extending downwardly exterior to said vessel at a point intermediate the upper and lower ends of said vessel where it terminates in a closed lower end and a plurality of lateral conduits connected between the side wall and said third conduit each lateral conduit communicating a separate side port with said third conduit.

JEWELL S. PALMER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,496,090 Marker et al June 3, 1924 2,451,803 Campbell et al Oct. 19, 1948 2,494,337 Hemminger Jan. 10, 1950 

